| Abstract |
Densities of dilute solutions of the electrolytes tetraethylphosphonium iodide and tetraethylammonium iodide in the nonaqueous solvents methanol, ethanol, 1-propanol, 1-butanol, acetonitrile, and 2-propanone were measured at 25degreesC. Using published values for the Debye-Huckel limiting slopes A(V), apparent molar volume data were fitted to the Pitzer equation yielding infinite-dilution partial molar volumes (V) over bar (infinity)(i) deviation parameters B-V. It is found that the variation in the van der Waals volume of the cationic central atoms is about one half the experimental volume change in 2-propanone solutions, but twice that value in the other five solvents. This finding is interpreted in terms of openness of solute structure and solvent penetration. Parameter B-V for each salt is shown to be solvent dependent. An interesting approximate linear variation between A(V) and B-V parameters is suggested by the data. This empirical relationship would entail correlation of short- and long-range interionic interactions in solution. |
